as previously made obvious, im still rather new to model Ts, and theres still so much left for me to learn, but what seems to be escaping my understanding most of all is the ignition system
its to my understanding the model T has a magneto which catches a magnetic current from the flywheel which is then fed into coils, which feed into the spark plugs.. however, magneto devices on other systems ive looked at seem to have a coil as part of the magneto itself.
im curious to learn more about ignition system upgrades ive read about... true fire is one, and ive heard of some people running a distributor on their model Ts as well so i was curious as to how those are typically set up?.
i have to wait a while before i can get a T to start working on, so until them im looking to learn more, when it does come time for me to rebuild one im still rather split on what i want as far as certain aspects go.. part of me wants to stay with the origional ignition, and the other part sees an automatic advance as a safety issue (many poor drivers on the road, freeing up brainpower used to tune the spark advance can be used defending myself from these drivers)
Justin, where do you live? You need to get hooked up with someone locally that has a T. You could look over it and ask questions. Seeing things visually while having them explained would help you to understand easier.
A couple of good sources: the MTFCA book on The Electrical System and the corresponding MTFCA video which will demonstrate what's in the book.
The choice of original ignition or "improvements" is a never-ending argument. Some say original is more dependable. Others think a distributor is better. I'm with the bunch that thinks the original system is part of what makes a Model T a Model T.
The Model T Ford "magneto" is actually what an engineer today would call an Alternating Current Generator, or AC Generator. It makes AC voltage from about 6 volts at idle speed, up to 30 volts at full speed. The variable voltage and frequency of the Model T "magneto" provides an elegant way to advance the timing as the engine speed increases. It is widely misunderstood, both because of its utter simpiity, and the complex set of benefis it provides. Most importantly it is extremely reliable, like the rest of the car.
A true magneto as found on other brands of car in the Model T era is a much different device, capable of delivering a high voltage spark without any external parts.
Ford used the term "magneto" to describe the Model T ignition system because he knew that people would instantly understand that the car would not require a battery to operate. This was very important in 1908 because batteries were expensive and unreliable. Ford's previous low price cars (Model N-R-S) had to have the battery recharged every few days or every few hundred miles because there was no magneto.
Justin, take the advice of above members and until you can get your T to tinker with, read to absorb all the info that you can or find a member with a T to buddy with. Unless you are going to restore a T for show judging purposes, it makes no difference what modifications are made to it, as long as they are done right, and with safety in mind.
Going back to your original post, which caused so much contriversy, I'll repeat, "a Model T is not a car to be used as a replacement for a DAILY DRIVER under any circumstances; especially in Pennsylvania. I know the winter temperatures up there. Are you going to be willing to work on and drive a T when its freezing or below zero? Yes, folks did it in the old days, because they had no choice.
A T can be a fun car to play with, but unless you live with Amish people and no automobiles are within 50 to 100 miles of where you live, a T is best limited to its use on public roads. I know some members have taken coast to coast trips and trips from Texas to Alaska, but they were either in group tours or were seasoned T owners and drivers with well setup cars and trip plans with all contentions planned for. Do yourself a favor and try to learn all you can from books and then ask your detailed questions about your T on the forum when you have one and then have fun with it as a play toy, not a daily driver.
95% of fixing anything is knowing how it works. As a design engineer I worked with high tech most of my career. There is an assumption that all things new are better than most things old. This can trap one into thinking that the obvious thing to do is "upgrade" everything on a T that has ever caused a problem for anyone. It would be somewhat easy to simply replace everything on a model T with modern technology. Before doing that - make sure you fully understand how something works and ask yourself why you bought a model T in the first place. My model T has some upgrades. I fully understand what I replaced and why I did it. I did not do it as a result of someone elses' inability to fix something but rather of my own understanding of what the issue was. Only if you make the original car work as designed can you then have ability to make your own decision as to what really needs to be upgraded. The fun part for me is now watching "old" technology like a coil-per-cylinder that the T used being now revisited and in fact proven as the "new" technology on modern cars. Do your own thinking on the various subjects but do so from a point of view of history and your own basic intelligence. The Model T is a piece of history. Your T when you get it is for you to have fun with and be safe with but also to preserve for the next generation to be able to do the same. If you totally updgrade it you may discover it isn't as much fun any more and yours will have slipped from its rightful place in history.
I would challenge you to do some research into the cars that went cross country in 2009 from NY to Seattle. Be a skeptic and remember that Ford built and sold more than 15 million T's that had no upgrades. Several of those NY-to-Seattle cars that drove last year made it with totally stock systems while some of the modern technology added to other cars didn't do as well. Find out why - for yourself and by yourself - find out why. Reject opinions - including mine - and use facts only. Facts are not a preponderance of prevailing opinions.
Here are some books you might read. Also, check out your local library, they are sure to have some books on the T.
There are basically two types of magnetos, high tension and low tension. A high tension magneto is what you're used to seeing. It's output is a high voltage, ready for the spark plug. A low tension mag is simply a generator/alternator who's output is required to go through an ignition coil to be of any use for a spark plug application. (it's o.k. however for make-and-break ignition but that's another story)
So, what the T has is a low tension magneto. It's output is directed to one of four ignition coils, depending on what cylinder needs to fire next. There is a separate coil for each spark plug. The device that picks out what coil to fire is called a timer, or commutator, that is driven off the camshaft.
The neat thing about the whole system is that while the timer might decide what coil will fire next, it's the timed, designed in, arrival of the magneto pulse, (the output is AC), that actually triggers the spark. Kind of like a crankshaft position sensor in todays cars. There's more detail than that to the whole system but those are the basics, (which is probably alll I'm able to communicate).
I have two Model T's. One a '19 Touring, one a '17 Depot Hack. On the Hack I have one O John's HSBK Charging systems, the other a brand I wont name. The vehicles both have tail and stop ligjts for safety reasons. I am now setting up a signal light system on the depot hack for again safety reasons. Neither of the two vehicle sre daily drivers. They are not show cars, however the Hack may be as it is the only one north of Sacaramento as far as I can find out from some of the guys here in town.
GO AND FIND AND BUY A MODLEL T AND REALLY GET down and dirty learning all you can about your car and then start asking "LOGICAL' questions that make sense to the rest of us. You I can assure you will have a lot of questions about the car, I sure as H*** did and now I enjoy both of them. Just my side of the story. I want the cars to last for a long time and we, Model T owners are the ones who can make it happen. It would be nice if we caould come up with the real time and know how many "T"'s are really still alive and running, not just the derelicts, complete and running and driveable!
I seem to remember a 2-part, in-depth explanation with some line drawings, of the workings of the Model T ignition posted on this forum, but I can't seem to find it. Anybody have that link?
I think most of what I would have posted has already been said. But I will add a few cents worth. A person will usually buy a Model T because of the history that goes with it, or because he/she likes the way they look etc. The understanding when one buys a Model T, is that it is not the fastest car in the world, but it is indeed faster than a horse, and we must remember that the horse was it's chief competitor in the day.
To change something on a Model T is not necessarily an upgrade, but it is a fix for a problem which exists. The distributor or the trufire, is usually used because the magneto does not work anymore, or because the coils have ceased their function. When the function of the ignition ceases, one must make the decision to fix the problem, or to replace it.
Both distributor and trufire will replace a bad ignition system without major work to the engine. To fix the magneto might require removal of the engine. It usually fails when the end play of the rear main bearing gets to great and the magnets distance from the coil ring too great to produce the desired current. Or it can be caused by cut coils or deterioriated insulation on the coil ring. The magnets can also loose their magnetism.
The coils can be bad, most often by the condensor(capicitor) deteriorated. Or the points need to be replaced or windings open or shorted.
All the above problems can be fixed by an amatuer craftsman with simple tools. The only tool needed for a good adjustment of the coils is a coil tester. Usually someone in the area has one and will let the owner of the coils use it to adjust their coils. Or the coils can be mailed to an expert like Ron Patterson to be rebuilt.
There are also some who want to make the engine a little faster by removing weight from the flywheel and will remove the magnets. In that case the ignition system must be replaced with other type for the engine to run.
The original ignition system when properly maintained is dependable, reliable, and a good conversation piece when talking to the many people who will gather around the Model T wherever it is parked.
royce and jerry seemed to explain it perfectly... i know what a magneto is and from prior knowledge i didnt think ignition coils were neccessary, so my confusion was if it had a magneto (as previously thought to be a magneto being specifically a high tension mag) then why would it need coils? but yeah, makes perfect sense now
what i dont understand though. and im not suggesting any modifications or ideas of the such... but wouldnt it have been easier to have a "high tension" magneto create the neccessary spark for the spark plug with a switch to send it to the proper plug, instead of a sort of switch to send the 6 volts to the proper coil which then in turn goes to the plug?
Justin. Don't worry about the advance not being automatic. The more you drive the T, everything becomes automatic. Changing gears, stopping,controlling the throttle and spark advance, steering. Once you are used to it, you wouldn't want it any other way. Just my 2 cents worth.
yeah, youre probably right.. i ride motorcycles a lot and at this point im not even sure if they make automatic trannies for those.. but i upshift, and downshift instinctively when my brain detects a certain pitch representative of the engines RPMs..
im sure the same thing would happen with a model T where your brain automatically and subconciously associates a certain pitch of the engine or vibration with the need to do move a lever
Justin -- Since this thread has morphed from its original question into a topic about driving Model T's, I'll add about 2 cents' worth. The Model T is inherently more simple to drive than other manual transmission cars, even though it seems a bit strange to folks today who have not driven them before. "Back in the day", if you qualified for a driver's license using a Model T, many states issued you a license which was for Model T's only. If you wanted to drive one of those more complicated sliding-gear transmissions, you needed to use one of those for your driver's test. When first driving a Model T these days, it seems awkward at first because it is different. But after some practice, it becomes automatic because it is inherently very simple. All it takes is a bit of practice, and you'll be driving a T like a veteran in no time.
well walker, im willing to give anything a try.. ill try it that way for a couple months, but ive made no secret i intend to dive into the aftermarket and make a T safe for daily driving, which means better brakes, tail lights, turn signals too
at this point im guessing a spare coil is something a lot of T owners carry on the vehicle as a spare?
I'll venture a guess as to why the four individual coils and low tension nagneto. Carry over from previous models. The mag was nothing more than a means to power an existing ignition system. And that's the beauty of it. People talk about reliability. The model T has a redundant power source for the ignition system, battery AND magneto. Even the early cars had a provision for attaching a battery (Usually several dry cells wired in series) to power the coils for use in starting or for backup in case of mag failure.
Another note on reliability. The ignition system is not prone to sudden and catestrophic failure. Debris at the mag pick up or a short or open of the field coil may cause the mag to quit, but the battery will get you home. All 4 coils are not going to go bad at once. You can get home on 3. The timer is not likely to fail outright. You will likely notice poor performance due to a worn timer a LONG time before outright failure. Don't let the thing scare you!
Get a chanch to drive a T before you worrie about all the what iff's.After a drive you may not wan't a T?? Bud.
At these two links, you'll find comprehensive, wonderfully written and illustrated information on the workings of the Model T's ignition system.